Apparatus and methods for repairing composite laminates

ABSTRACT

An apparatus and methods include infusing the flowable matrix material into a space in the composite laminate through the use of a formed hole extending at least partially through the composite laminate. In addition, the apparatus and methods include infusing the flowable matrix material into a space in the composite laminate in a stepwise manner in order to obtain more complete filling of such space.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application relies for priority on U.S. Provisional PatentApplication Ser. No. 62/313,271, entitled “APPARATUS AND METHODS FORREPAIRING COMPOSITE LAMINATES,” filed Mar. 25, 2016, the entire contentof which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The disclosure relates generally to repairing composite laminates, andmore particularly to repairing defects such as porosity and/or edgedelamination in composite laminates by infusion of flowable matrixmaterial.

BACKGROUND OF THE ART

When manufacturing composite laminates, damage can occur to suchlaminates during processing or subsequent handling. For example,relatively heavy surface porosity extending up to about 40% through thethickness of a composite laminate can occur due to a processing errorduring manufacturing (e.g., resin transfer infusion). Also, handlingaccidents such as an impact to an edge of a composite laminate canresult in edge delamination.

Methods for repairing these types of damage exist. For example, withrespect to repairing porosity, a resin of suitable viscosity can bespread over the surface of the laminate to restore the cosmeticappearance and hinder moisture ingress into the composite laminate. Suchrepair method is also known as a “resin rub” on the surface of thecomposite laminate and typically only wets the outer surface ply of thecomposite laminate and seals the porosity within the component. Suchresin rub is typically not considered a structural repair becauseporosity can still be present below the outer surface of the compositelaminate. Such resin rub can also require a significant amount of reworkto restore an acceptable surface finish for the composite laminate.

With respect to edge delamination, one known method includes the manualintroduction of resin into the delamination using a hypodermic syringefor example and the subsequent clamping of the affected region of thecomposite laminate during curing. This type of repair may not alwayscompletely fill the space in the composite laminate associated with thedelamination with resin and therefore may not restore the structuralperformance of the composite laminate. Improvement is desirable.

SUMMARY

In one aspect, the disclosure describes an apparatus for infusing aflowable matrix material into a porous region in a composite laminatevia a surface of the composite laminate. The apparatus comprises:

a vacuum barrier covering at least a first portion of an area of thesurface of the composite laminate overlaying a location of the porousregion in the composite laminate, the vacuum barrier defining anenclosed volume comprising the first portion of the area of the surfaceof the composite laminate;

a supply of flowable matrix material available to the first portion ofthe area of the surface of the composite laminate;

a flow barrier hindering a flow of the flowable matrix material out ofthe first portion of the area via the surface of the composite laminate;and

a vacuum source in fluid communication with the enclosed volume andconfigured to cause the flowable matrix material in the first portion ofthe area to be drawn into the porous region, the vacuum source being influid communication with a second portion of the area outside the firstportion of the area to draw the flowable matrix material out of theporous region via the second portion of the area.

The vacuum barrier may also cover the second portion of the area and theenclosed volume may include the second portion of the area.

The apparatus may comprise:

a first carrier configured to facilitate the distribution of flowablematrix material across at least some of the first portion of the area;and

a second carrier configured to facilitate the flow of flowable matrixmaterial exiting the second portion of the area toward the vacuumsource.

The flow barrier may comprise a gap between the first carrier and thesecond carrier.

The flow barrier may comprise a release film overlaying the first andsecond carriers and extending across the gap between the first carrierand the second carrier.

The composite laminate may comprise a formed hole extending at leastpartially through the composite laminate from the surface inside thefirst portion of the area to facilitate the infusion of flowable matrixmaterial into the porous region. The apparatus may comprise a structuralpin extending into the formed hole where the structural pin may beconfigured to define a passageway for the flowable matrix materialbetween the structural pin and a wall of the formed hole.

The structural pin may protrude from the surface of the compositelaminate.

The structural pin may comprise fibrous material.

The apparatus may comprise a flexible caul plate disposed inside theenclosed volume.

In another aspect, the disclosure describes a method for infusing aflowable matrix material into a porous region in a composite laminatevia a surface of the composite laminate where the surface comprises anarea overlaying a location of the porous region in the compositelaminate. The method may comprise:

supplying the flowable matrix material to a first portion of the area ofthe surface of the composite laminate;

distributing the flowable matrix material across at least some of thefirst portion of the area of the surface; and

while hindering a flow of the flowable matrix material out of the firstportion of the area via the surface of the composite laminate, drawingthe flowable matrix material in the first portion of the area into theporous region and causing some of the flowable matrix material to exitthe porous region via a second portion of the area outside the firstportion of the area.

The method may comprise:

using a vacuum source to draw the flowable matrix material into theporous region; and

facilitating the flow of flowable matrix material exiting the porousregion via the second portion away from the second portion.

The method may comprise forming a hole through the surface of thecomposite laminate in the first portion of the area defining thelocation of the porous region where the hole is formed before drawingthe flowable matrix material to facilitate the drawing of flowablematrix material into the porous region.

The method may comprise providing a structural pin in the formed holewhere a passageway for the flowable matrix material is defined betweenthe structural pin and a wall of the formed hole where the structuralpin is provided before drawing the flowable matrix material.

The method may comprise curing the flowable matrix material drawn intothe porous region and that has entered the formed hole, while thestructural pin is in the formed hole.

The method may comprise detecting some of the flowable matrix materialexiting the porous region via the second portion of the area and ceasingthe drawing after having detected some of the flowable matrix materialhaving exited the porous region via the second portion.

In another aspect, the disclosure describes a method for repairing acomposite laminate by infusion of a flowable matrix material. The methodmay comprise:

infusing the flowable matrix material into a space in the compositelaminate and into a passageway in fluid communication with the space,the passageway being defined between a structural pin disposed in aformed hole extending at least partially through the composite laminate,and, a wall of the formed hole; and

curing the flowable matrix material infused into the space and into thepassageway while the structural pin is in the formed hole.

A ratio of a diameter of the structural pin over a diameter of theformed hole may be about ⅔.

The formed hole and the structural pin may extend through two or moreplies of the composite laminate.

The method may comprise infusing the flowable matrix material into thespace in the composite laminate via the passageway.

The method may comprise infusing the flowable matrix material into thepassageway via the space in the composite laminate.

The method may comprise detecting some of the flowable matrix materialhaving entered the passageway and ceasing to infuse the flowable matrixmaterial into the space after having detected some of the flowablematrix material having entered the passageway.

In another aspect, the disclosure describes a composite laminatecomprising:

a volume of cured flowable matrix material infused into the compositelaminate, the volume of cured flowable matrix material comprising acolumn of cured flowable matrix material extending at least partiallythrough the composite laminate; and

a structural pin disposed in the column of cured flowable matrixmaterial.

The structural pin may extend generally along the column of curedflowable matrix material and has an outer diameter that is smaller thana diameter of the column of cured flowable matrix material.

A ratio of the diameter of the structural pin over the diameter of thecolumn may be about ⅔.

The structural pin may comprise a fibrous material.

The column of cured flowable matrix material and the structural pin mayextend through two or more plies of the composite laminate.

In another aspect, the disclosure describes an apparatus for repairingedge delamination in a composite laminate by infusion of a flowablematrix material via an edge of the composite laminate. The apparatuscomprises:

a supply of flowable matrix material coupled to a space in the compositelaminate associated with the edge delamination via the edge of thecomposite laminate; and

a first vacuum source coupled to the space in the composite laminateassociated with the edge delamination via a first hole in a face of thecomposite laminate for causing the flowable matrix material to flow fromthe edge of the composite laminate into the first hole via the spaceassociated with the edge delamination.

The first vacuum source or a second vacuum source may be coupled to thespace in the composite laminate associated with the edge delaminationvia a second hole in the face of the composite laminate for causing theflowable matrix material to flow from the edge of the composite laminateinto the second hole via the space associated with the edgedelamination.

The first hole may be at a first distance from the edge and the secondhole may be at a second distance from the edge where the second distancemay be greater than the first distance.

The apparatus may comprise a first vacuum barrier covering a first areaof the face of the composite laminate. The first vacuum barrier maydefine a first enclosed volume in fluid communication with the space inthe composite laminate associated with the edge delamination via aplurality of first holes in the face of the composite laminate.

The apparatus may comprise a second vacuum barrier covering a secondarea of the face of the composite laminate where the second area isdifferent from the first area. The second vacuum barrier may define asecond enclosed volume in fluid communication with the space in thecomposite laminate associated with the edge delamination via a pluralityof second holes in the face of the composite laminate.

The first vacuum source may be coupled to the space in the compositelaminate associated with the edge delamination via a first valveactuatable from an open to a closed position substantially preventingfluid flow via the first hole.

In another aspect, the disclosure describes a method for repairing edgedelamination in a composite laminate by infusion of a flowable matrixmaterial. The method comprises:

infusing the flowable matrix material into the space associated with theedge delamination in the composite laminate using a pressuredifferential between a first inboard location on the composite laminateand an edge location on the composite laminate, the first inboardlocation being in fluid communication with the edge location via thespace in the composite laminate; and curing the flowable matrix materialinfused into the space in the composite laminate associated with theedge delamination.

The method may comprise infusing the flowable matrix material into thespace via the edge location.

The method may comprise lowering a pressure at the first inboardlocation relative to a pressure at the edge location to draw theflowable matrix material from the edge location toward the first inboardlocation.

The method may comprise lowering the pressure at the first inboardlocation via a hole extending at least partially through the compositelaminate from a face of the composite laminate.

The method may comprise infusing the flowable matrix material into thehole.

The structural pin may extend into the hole and the flowable matrixmaterial may be infused into a passageway defined between a wall of thehole and the structural pin.

The method may comprise curing the flowable matrix material that hasentered the hole while the structural pin is in the hole.

The method may comprise detecting some of the flowable matrix materialhaving entered the hole and ceasing to infuse the flowable matrixmaterial into the space associated with the delamination in thecomposite laminate after having detected some of the flowable matrixmaterial having entered the hole.

The method may comprise infusing the flowable matrix material into thespace via the first inboard location.

The method may comprise lowering a pressure at the edge locationrelative to a pressure at the first inboard location to draw theflowable matrix material from the first inboard location toward the edgelocation.

The method may comprise infusing the flowable matrix material via a holeextending at least partially through the composite laminate from a faceof the composite laminate.

The method may comprise infusing the flowable matrix material into thespace associated with the delamination in the composite laminate using apressure differential between the edge location and a second inboardlocation in the composite laminate where the second inboard location isin fluid communication with the edge location via the space in thecomposite laminate associated with the delamination.

The method may comprise infusing the flowable matrix material into thespace via the second inboard location.

The method may comprise ceasing to infuse the flowable matrix materialinto the space associated with the delamination in the compositelaminate using the first inboard location before infusing the flowablematrix material into the space associated with the delamination in thecomposite laminate using the second inboard location.

The method may comprise substantially hermetically sealing the firstinboard location before infusing the flowable matrix material into thespace associated with the delamination in the composite laminate usingthe second inboard location.

The first inboard location may be at a first distance from the edgelocation and the second inboard location may be at a second distancefrom the edge location. The second distance may be greater than thefirst distance.

In another aspect, the disclosure describes a composite laminate withedge delamination in preparation for repair by infusion of a flowablematrix material. The composite laminate comprises:

a space in the composite laminate associated with the edge delamination,the space being in fluid communication with an edge of the laminatecomposite; and a first formed hole at a first inboard location in thecomposite laminate, the first formed hole extending from a face of thecomposite laminate and at least partially through the compositelaminate, the first formed hole being in fluid communication with thespace in the composite laminate associated with the edge delamination.

The composite laminate may comprise a first structural pin extendinginto the first formed hole.

The first structural pin may have an outer diameter that is smaller thana diameter of the first formed hole to permit the passage of theflowable matrix material between the first structural pin and a wall ofthe first formed hole.

A ratio of the diameter of the structural pin over the diameter of theformed hole may be about ⅔.

The composite laminate may comprise a second formed hole at a secondinboard location on the composite laminate. The second formed hole mayextend from the face of the composite laminate and at least partiallythrough the composite laminate. The second formed hole may be in fluidcommunication with the space in the composite laminate associated withthe edge delamination.

The first formed hole may be at a first distance from the edge locationand the second formed hole may be at a second distance from the edgelocation. The second distance may be greater than the first distance.

In a further aspect, the disclosure describes a method for infusing aflowable matrix material into a space in the composite laminate. Themethod comprises:

supplying the flowable matrix material at an inlet location on thecomposite laminate, the inlet location being in fluid communication withthe space in the composite laminate;

infusing the flowable matrix material into the space in the compositelaminate using a pressure differential between the inlet location and afirst location in the composite laminate, the first location being influid communication with the inlet location via the space in thecomposite laminate;

ceasing to infuse the flowable matrix material into the space using thefirst location;

infusing the flowable matrix material into the space in the compositelaminate using a pressure differential between the inlet location and asecond location in the composite laminate, the second location being influid communication with the inlet location via the space in thecomposite laminate; and ceasing to infuse the flowable matrix materialinto the space using the second location.

The first location may be at a first distance from the inlet locationand the second location may be at a second distance from the inletlocation. The second distance may be greater than the first distance.

The method may comprise lowering a pressure at the first locationrelative to a pressure at the inlet location via a first formed holeextending at least partially through the composite laminate from a faceof the composite laminate.

The method may comprise ceasing to infuse the flowable matrix materialinto the space associated with the delamination in the compositelaminate using the first formed hole after some of the flowable matrixmaterial has entered the first formed hole.

The method may comprise hermetically sealing the first formed holebefore infusing the flowable matrix material into the space in thecomposite laminate using the second location.

The method may comprise curing the flowable matrix material that hasentered the first formed hole while a first structural pin is in thefirst formed hole.

The method may comprise lowering a pressure at the second locationrelative to the pressure at the inlet location via a second formed holeextending at least partially through the composite laminate from theface of the composite laminate.

The method may comprise ceasing to infuse the flowable matrix materialinto the space associated with the delamination in the compositelaminate using the second formed hole after some of the flowable matrixmaterial has entered the second formed hole.

Further details of these and other aspects of the subject matter of thisapplication will be apparent from the detailed description and drawingsincluded below.

DESCRIPTION OF THE DRAWINGS

Reference is now made to the accompanying drawings, in which:

FIG. 1 is a schematic cross-sectional illustration of an exemplaryapparatus for repairing a porous region in a composite laminate byinfusion of flowable matrix material;

FIG. 2 is a schematic top plan view of a distribution carrier andoverflow carriers of the apparatus of FIG. 1 disposed over the compositelaminate;

FIG. 3 is an exploded schematic cross-sectional illustration of theapparatus of FIG. 1 showing the flow path of flowable matrix material;

FIG. 4 is a flowchart illustrating an exemplary method for infusingflowable matrix material into the porous region of the compositelaminate of FIG. 1;

FIG. 5A is a partial schematic cross-sectional view of the compositelaminate of FIG. 1 at a formed hole extending from a face of thecomposite laminate before infusion;

FIG. 5B is a partial schematic cross-sectional view of the compositelaminate of FIG. 1 at a column of cured flowable matrix materialextending from a face of the composite laminate after infusion;

FIG. 6A is a partial schematic cross-sectional view of the compositelaminate of FIG. 1 at a formed hole extending from the face of thecomposite where a structural pin has been inserted into the formed holebefore infusion;

FIG. 6B is a partial schematic cross-sectional view of the compositelaminate of FIG. 1 at a column of cured flowable matrix materialextending from the face of the composite laminate after infusion wherethe structural pin is disposed in the column;

FIG. 7 is a perspective view of an exemplary face of the compositelaminate comprising dry fibers where the face comprises holes andstructural pins inserted in the holes;

FIG. 8 is an enlarged perspective view of an exemplary hole formed inthe face of composite laminate shown in FIG. 7 with a structural pinextending in the hole;

FIG. 9 is a flowchart illustrating an exemplary method for repairingcomposite laminate by infusion of flowable matrix material into a spacein the composite laminate of FIG. 1;

FIG. 10 is a perspective view of an edge of an exemplary compositelaminate comprising delamination damage;

FIG. 11 is a schematic cross-sectional illustration of an exemplaryapparatus for repairing delamination damage in the composite laminate ofFIG. 10;

FIG. 12A is a partial schematic cross-sectional view of the compositelaminate of FIG. 10 at a formed hole extending from a face of thecomposite laminate before infusion;

FIG. 12B is a partial schematic cross-sectional view of the compositelaminate of FIG. 10 at a column of cured flowable matrix materialextending from the face of the composite laminate after infusion;

FIG. 13A is a partial schematic cross-sectional view of the compositelaminate of FIG. 10 at the formed hole extending from the face of thecomposite laminate where a structural pin has been inserted into theformed hole before infusion;

FIG. 13B is a partial schematic cross-sectional view of the compositelaminate of FIG. 10 at a column of cured flowable matrix materialextending from the face of the composite laminate after infusion wherethe structural pin is disposed inside the column;

FIG. 14 is a perspective view of part of an exemplary embodiment of theapparatus of FIG. 11;

FIG. 15 is a flowchart illustrating an exemplary method for repairingdelamination damage in the composite laminate of FIG. 10 by infusion offlowable matrix material via an edge of the composite laminate;

FIG. 16 is a flowchart illustrating an exemplary method for repairingedge delamination damage in the composite laminate of FIG. 10 byinfusion of flowable matrix material; and

FIG. 17 is a flowchart illustrating an exemplary method for infusingflowable matrix material into a space in a composite laminate in astepwise manner.

DETAILED DESCRIPTION

The present disclosure relates to repairing defects in compositelaminates that are introduced either during manufacturing or afterward.In various embodiments, methods and apparatus disclosed herein may, forexample, be suitable for repairing defects in a composite laminate suchas, for example, dry fibers, surface porosity and/or internal porositythat may have been introduced during manufacturing (e.g., during resintransfer infusion), or, delamination(s) at an edge of the compositelaminate that may have been caused by an impact to the edge of thecomposite laminate during handling or during use. In variousembodiments, the methods and apparatus disclosed herein may provide morecomplete filling of such defects with flowable matrix material (e.g.,resin) and may therefore provide repaired composite laminates withimproved structural performance.

The apparatus and methods disclosed herein may be used for repairingparts (e.g., laminates) of composite materials comprisingfibre-reinforced structures (e.g., containing carbon, quartz glass,e-glass and/or other fibres) by resin infusion. For example, apparatusand methods disclosed herein may be used to repair parts manufactured byresin infusion processes such as resin transfer infusion (RTI), resintransfer molding (RTM), vacuum-assisted resin transfer molding (VARTM),vacuum-assisted resin infusion (VARI) and Seemann composites resininfusion molding process (SCRIMP) for example. Such parts may includeparts for use in aerospace or other applications, such as for windturbines, radomes or automotive parts. For example, within aerospaceapplications, such parts may include aircraft parts such as fuselage andwing components such as spars, skins and also nacelle components foraircraft engines. In some embodiments, the apparatus and methodsdisclosed herein may be used to repair regions of composite parts thathave not been completely impregnated with resin during manufacturing orthat have been damaged.

Apparatus and methods disclosed herein may be used to repair partsmanufactured by processes other than resin infusion. For example,apparatus and methods disclosed herein may be used to repair partsmanufactured using fibrous material that has been pre-impregnated with aresin system also known as “prepregs”.

Aspects of various embodiments are described through reference to thedrawings.

FIG. 1 is a schematic cross-sectional illustration of an exemplaryapparatus 10 for repairing porous region 12 in composite laminate 14 byinfusion of flowable matrix material (e.g., resin) 16 via face 18 ofcomposite laminate 14. For the purpose of the present disclosure, a“face” of composite laminate 14 is intended to represent a (e.g., frontor rear, prominent) surface of composite laminate 14 extending generallyalong (e.g., parallel to) one or more plies 52 (see FIGS. 2 and 5A) ofcomposite laminate 14. Composite laminate 14 may have a flat panelconfiguration with a uniform thickness as shown in FIG. 1.Alternatively, it is understood that composite laminate 14 could becurved and/or have a varying thickness provided by ply starts anddrop-offs for example.

Apparatus 10 may be used to repair defects such as porosity (e.g.,voids, space, cracks) formed into composite laminate 14 duringmanufacturing or at some other time. Resin infusion processes such asresin transfer infusion (RTI), resin transfer molding (RTM),vacuum-assisted resin transfer molding (VARTM), vacuum-assisted resininfusion (VARI) and Seemann composites resin infusion molding process(SCRIMP) are known processes used for manufacturing composite laminatescomprising fibre-reinforced structures. Occasionally, and depending onfactors associated with such infusion processes, there can be dry fabricpatches at the surface of fibre-reinforced parts that were notcompletely impregnated with resin during the process. Such a dry fabricpatch can comprise porosity such as porous region 12 extending up toabout 40% through the thickness of a composite structure such ascomposite laminate 14 for example. In some situations, depending onspecific process parameters, a part produced by the RTI process canexhibit porosity extending up to 40% into the thickness of the partwithout a flow (e.g., vacuum) path extending from face 18 to some of thevoids in porous region 12. Alternatively, porous region 12 may beassociated with a manufacturing process other than resin infusion usedto produce composite laminate 14 from, for example, prepreg material(s).

Apparatus 10 may comprise one or more vacuum barriers 20 (i.e., vacuumbags) (referred hereinafter in the singular) covering area 22 of theface 18 of composite laminate 14 defining a location of porous region 12in composite laminate 14. The extent of porous region 12 defined by area22 may be determined by way of non-destructive (i.e., ultrasound)inspection. Vacuum barrier 20 may define an enclosed volume 24comprising at least part of area 22 defined on face 18 of compositelaminate 14. In various embodiments, volume 24 may include only firstportion 28 of area 22, or, volume 24 may include both first portion 28and second portion 36 of area 22. Vacuum barrier 20 may comprise asuitable polymer (e.g., nylon) flexible sheet and may be of the type(s)typically used as flexible bagging membranes (i.e., vacuum bags) inknown or other resin infusion processes. Vacuum barrier 20 may besubstantially gas-impermeable. Vacuum barrier 20 may be sealed to face18 of composite laminate 14 via one or more sealing members 26. In someembodiments, sealing member(s) 26 may comprise a suitable sealant ordouble-sided tape. Sealing between vacuum barrier 20 and compositelaminate 14 may not be absolutely hermetic but may be suitable forachieving at least some differential pressure between volume 24 and theatmosphere.

Apparatus 10 may comprise a supply of flowable matrix material 16available to first portion 28 of area 22 defined on face 18 of compositelaminate 14. Flowable matrix material 16 may be supplied to firstportion 28 of area 22 via inlet port 29. Flowable matrix material 16 mayhave a viscosity that is temperature-dependent. Accordingly, in someembodiments, apparatus may also comprise suitable heating means such asan electrically-powered heating blanket for applying heat to flowablematrix material 16 and optionally to part of composite laminate 14 to beinfused with flowable matrix material 16.

In various embodiments, flowable matrix material 16 may comprise anyresin suitable for the particular application. For example, flowablematrix material 16 may include an epoxy-based resin. Such epoxy-basedresin may be a one-part liquid epoxy resin or a two-part liquid epoxyresin. In some embodiments, flowable matrix material 16 may be of thetype sold under the trade name CYCOM 890 by CYTEC ENGINEERED MATERIALS.In some embodiments, flowable matrix material 16 may be of the type soldunder the trade name HEXFLOW RTM 6 by HEXCEL. In some embodiments,flowable matrix material 16 may be a two-part liquid resin system suchas product number EA9396 sold under the trade name HYSOL or of the typesold under the trade name CYCOM 823 by CYTEC ENGINEERED MATERIALS. Othertypes of cosmetic or structural resins may also be suitable for use asflowable matrix material 16 with the apparatus and methods disclosedherein.

Apparatus 10 may comprise one or more flow barriers 30 (referredhereinafter in the singular) hindering the flow of flowable matrixmaterial 16 out of first portion 28 of area 22 via face 18 of compositelaminate 14. Flow barrier 30 may comprise any suitable component servingto hinder flowable matrix material 16 from flowing across face 18 ofcomposite laminate 14 beyond first portion 28 of surface area 22.Accordingly, flow barrier 30 may serve as a dam to the flow front offlowable matrix material 16. Flow barrier 30 may be a single element(e.g., a sealing member such as sealing member 26) or may include two ormore elements cooperating together to achieve some hindrance to the flowof flowable matrix material 16 across face 18. For example, in someembodiments, a dry carbon cloth may serve as barrier 30 to slow/hinderthe flow front of flowable matrix material 16 out of first portion 28 ofarea 22. Alternatively, in some embodiments, flow barrier 30 may beachieved by way of a double bagging arrangement where a first bag (e.g.,vacuum barrier 20) would be installed to cover first portion 28 of area22 of face 18 and a separate second bag (e.g., vacuum barrier 20) wouldbe installed to cover second portion 36 of area 22 of face 18 so as toprevent the flow of flowable matrix material 16 across face 18 and outof first portion 28 of area 22.

In some embodiments, flow barrier 30 may be defined by a gap G or breakin a carrier layer of apparatus 10 configured to facilitating theflow/distribution of flowable matrix material 16 across face 18 asillustrated in FIGS. 1-3. For example, apparatus 10 may comprisedistributing carrier 32 extending within at least part of first portion28 of area 22 to facilitate the distribution (i.e., spread) of flowablematrix material 16 across face 18 but only within first portion 28 ofarea 22. In some embodiments, distributing carrier 32 may comprise asuitable distribution mesh of known or other types. For example,distributing carrier 32 may be configured as a net and may be made ofnylon. Distributing carrier 32 may comprise open area through whichflowable matrix material 16 may flow during the repair procedure. Insome embodiments, distributing carrier 32 may comprise a glass or carboncloth configured to facilitate the flow of flowable matrix material 16across face 18.

Apparatus 10 may also comprise one or more overflow carriers 34(referred hereinafter in the singular) configured to facilitate the flowof flowable matrix material 16 exiting porous region 12 via one or moresecond portions 36 (referred hereinafter in the singular) of area 22toward one or more respective vacuum ports 38 during the repairprocedure. In some embodiments, overflow carrier 34 may be of the sameconstruction/type as distribution carrier 32. Second portion 36 of area22 may be disposed outside of first portion 28 of area 22. In theexemplary embodiment illustrated in FIG. 1, flow barrier 30 may bedefined by gap G between distributing carrier 32 and overflow carrier 34across which the flow of flowable matrix material 16 may be hinderedduring the repair procedure. Accordingly, first portion 28 of area 22may be separated from second portion 36 by gap G.

Alternatively or in addition, flow barrier 30 may comprise one or moresealing members of the same type as sealing member 26 or of some othertype. For example, such sealing member may be disposed betweendistributing carrier 32 and overflow carrier 34 (i.e., in gap G) so asto hinder the flow of flowable matrix material 16 out of first portion28 of area 22 by flowing across face 18.

Vacuum port 38 may be coupled to vacuum source 40 (e.g., vacuum pump)that may be used to evacuate gas/air from volume 24 prior, during and/orafter the infusion of flowable matrix material 16 into porous region 12.Accordingly, vacuum source 40 may drive the flow of flowable matrixmaterial 16 into porous region 12 primarily by drawing, by theapplication of a vacuum, flowable matrix material 16 from (e.g.,central) one or more inlet ports 29 toward one or more vacuum ports 38via porous region 12. For example, the application of such vacuum maycause flowable matrix material 16 to be drawn into porous region 12 viafirst portion 28 of area 22 and to exit porous region 12 via secondportion 36 of area 22 by virtue of flow barrier 30 hindering the flow offlowable matrix material across face 18 and thereby forcing flowablematrix material 16 into porous region 12. A plurality of inlet ports 29and/or a plurality of vacuum ports 38 may be used in some situationsdepending on the size and/or configuration of porous region 12 forexample.

The evacuation of volume 24 via vacuum port 38 may also cause thedifference in pressure between the atmosphere and volume 24 to pressvacuum barrier 20 downwardly toward face 18 of composite laminate 14 andthereby urge flowable matrix material 16 disposed inside of volume 24and above first portion 28 of area 22 against face 18 of compositelaminate 14 and thereby promote infusion of flowable matrix material 16into porous region 12.

As explained further below, composite laminate 14 may comprise one ormore optional drilled (or otherwise formed) holes 42 (referredhereinafter in the singular) extending from face 18 inside first portion28 of area 22 defined in face 18 and at least partially throughcomposite laminate 14 to facilitate the infusion of flowable matrixmaterial 16 into porous region 12. In some embodiments, an optionalstructural pin 44 may be disposed to extend into one, some or all formedholes 42. A passageway 54 (see FIG. 6A) for allowing the passage offlowable matrix material 16 therethrough may be defined betweenstructural pin 44 and a wall of formed hole 42. Structural pin 44 may bedisposed in formed hole 42 for the infusion of flowable matrix material16 and also left in formed hole 42 during curing of flowable material 16so as to remain in the repaired composite laminate 14 and providestructural reinforcement. Curing of flowable matrix material 16 may beconducted according to known or other methods based on the type offlowable matrix material 16 used.

Apparatus 10 may comprise flexible caul plate 46 and release film 48disposed inside volume 24. Flexible caul plate 46 may be disposedbetween vacuum barrier 20 and release film 48. Release film 48 may bedisposed between flexible caul plate 46 and distributing carrier 32. Insome embodiments, porous release medium 49 may be disposed betweendistributing carrier 32 and outer face 18 of part 14. In variousembodiments, release film 48 may comprise a cohesively formed plasticthat does not readily adhere to other polymers. Release film 48 may, forexample, comprise a fluorpolymeric film of the type sold under the tradename WRIGHTLON 5200 or under product number A4000 by AirtechInternational Inc. In some embodiments, porous release medium 49 maycomprise a polytetrafluorethylene (PTFE) coated fibreglass fabric of thetype sold under the trade name RELEASE EASE supplied by AirtechInternational Inc. Porous release medium 49 may comprise a plurality ofopenings through which flowable matrix material 16 may permeate duringthe infusion process. In some embodiments, porous release medium 49 may,for example, be of the type sold under product number A4000P by AirtechInternational Inc. Caul plate 46 may comprise an elastomeric materialproviding some flexibility. In some embodiments, caul plate 46 may bemade of a rubber or a rubber/silicone combination for example. The useof caul plate 46 may protect vacuum barrier 20 from getting punctured bystructural pin 44 that may protrude out of hole 42 so as to be raisedfrom face 18 of composite laminate 14.

FIG. 2 is a schematic top plan view of composite laminate 14 showingarea 22 defining the location of porous region 12. FIG. 2 also showsdistribution carrier 32 and overflow carrier 34 of apparatus 10overlaying area 22 as shown in FIG. 1. As explained above, distributioncarrier 32 may overlay first portion 28 of area 22 and may facilitatethe distribution of flowable matrix material 16 from inlet port 29across face 18 of composite laminate within first portion 28 of area 22only. Overflow carrier 34 may overlay second portion 36 of area 22 andextend toward vacuum port 38 so as to facilitate the flow of flowablematrix material 16 exiting second portion 36 of area 22 during infusiontoward vacuum port 38. During the evacuation of volume 24 via vacuumport 38, the gap G between distribution carrier 32 and overflow carrier34 may permit release film 48 and vacuum barrier 20 to be presseddownwardly toward face 18 of composite laminate 14 at the location ofgap G to form flow barrier 30 (e.g., dam) that hinders the flow offlowable matrix material 16 across gap G via face 18 of compositelaminate 14. For example, release film 48 (see FIG. 1) may extend acrossgap G and pressed downwardly toward face 18 during evacuation of volume24 so as to hinder the flow of flowable matrix material 16 on face 18across gap G.

FIG. 3 is an exploded schematic cross-sectional illustration ofapparatus 10 showing the flow path of flowable matrix material 16 duringinfusion. During the evacuation of volume 24, flowable matrix material16 may be urged downwardly against first region 28 of area 22 of face 18to cause infusion of flowable matrix material 16 into porous region 12while the flow of flowable matrix material 16 out of the first portion28 of area 22 via face 18 of composite laminate 14 is hindered by flowbarrier 30 (e.g., see downward arrows in first portion 28 of area 22).As porous region 12 becomes at least partially filled with flowablematrix material 16, excess flowable matrix material 16 in porous region12 may be permitted to exit (e.g., overflow) porous region 12 via secondportion 36 of area 22 where first portion 28 of area 22 may be in fluidcommunication with second portion 36 of area 22 via spaces/voids insideporous region 12. In some embodiments, first portion 28 of area 22 andassociated inlet port 29 may be disposed in an inner (e.g., central,radially inner) portion of area 22 so that flowable matrix material 16may enter a generally central portion of porous region 12 and exit agenerally outer (i.e., peripheral) region of porous region 12. In somesituations where a central portion of porous region 12 extends moredeeply into composite laminate 14, such flow path for flowable matrixmaterial 16 may facilitate a more complete (e.g., deeper) infusion ofporous region 12.

FIG. 4 is a flowchart illustrating an exemplary method 400 for infusingflowable matrix material 16 into porous region 12 in composite laminate14 via face 18 (or other surface) of composite laminate 14. In someembodiments, method 400 may be performed using apparatus 10 describedabove where face 18 of composite laminate 14 comprises area 22overlaying a location of porous region 12 in composite laminate 14.Method 400 may comprise: supplying flowable matrix material 16 to firstportion 28 of area 22 of face 18 of composite laminate 14 (see block402); distributing flowable matrix material 16 across at least some offirst portion 28 of area 22 (see block 404); and while hindering theflow of flowable matrix material 16 out of first portion 28 of area 22via face 18 of composite laminate 14, drawing flowable matrix material16 in first portion 28 of area 22 into porous region 12 and causing someflowable matrix material 16 to exit porous region 12 via second portion36 of area 22 where second portion 32 of area 22 is outside firstportion 28 of area 22 (see block 406).

In some embodiments, method 400 may comprise using vacuum source 40 todraw flowable matrix material into porous region 12 as explained above.The flow of flowable matrix material 16 exiting porous region 12 viasecond portion 36 of area 22 away from second portion 36 (e.g., towardvacuum port 38) may be facilitated by overflow carrier 34.

FIG. 5A is a partial schematic cross-sectional view of compositelaminate 14 at formed hole 42 extending from face 18 at least partiallythrough composite laminate 14 before infusion of flowable matrixmaterial 16 into porous region 12. FIG. 5B is a partial schematiccross-sectional view of composite laminate 14 at a corresponding column50 of cured flowable matrix material 16 extending from face 18 at leastpartially through composite laminate 14 after infusion of flowablematrix material 16 into porous region 12 and subsequent curing.

Formed hole 42 may be used in conjunction with the apparatus and methodsdisclosed herein. Hole 42 may be formed by mechanical drilling, laserdrilling or be otherwise formed into composite laminate 14 to facilitatethe infusion of flowable matrix material 16 into porous region 12 orother defect within composite laminate 14. Accordingly, formed hole 42may be formed prior to infusion of flowable matrix material 16 intoporous region 12. In some embodiments, the depth LH of hole 42 may beselected based on the depth of porous region 12 from face 18 ofcomposite laminate 14 so as to facilitate the infusion of flowablematrix material 16 to a desired depth into porous region 12. In someembodiments, depth LH of hole 42 may be selected to extend through twoor more plies 52 of composite laminate 14. In some embodiments, depth LHof hole 42 may be selected to extend completely through the thickness ofcomposite laminate 14.

Alternatively or in addition, hole 42 may be used to provide structuralreinforcement through the thickness (e.g., transverse, in the Zdirection) of composite laminate 14 after repair by allowing theformation of column 50 of cured flowable matrix material 16 extendingbetween plies 52 of composite laminate 14. The width or diameter DH ofhole 42 may be selected based on the expected viscosity of flowablematrix material 16 so that flowable matrix material 16 may flowadequately into hole 42. The width or diameter DH of hole 42 may beselected based on a desired corresponding width or diameter of column 50of cured flowable matrix material 16. Accordingly, in variousembodiments, the apparatus and methods disclosed herein may be used toproduce a composite laminate repaired by infusion of flowable matrixmaterial 16 and comprising volume 53 of cured matrix material 16 infusedinto porous region 12 of composite laminate 14 during repair and column50 of cured flowable matrix material 16 extending from face 18 ofcomposite laminate 14 and at least partially through composite laminate14.

FIG. 6A is a partial schematic cross-sectional view of compositelaminate 14 at formed hole 42 extending from face 18 at least partiallythrough composite laminate 14 where structural pin 44 has been insertedinto formed hole 42 before infusion of flowable matrix material 16 intoporous region 12. FIG. 6B is a partial schematic cross-sectional view ofcomposite laminate 14 at a corresponding column 50 of cured flowablematrix material 16 extending from face 18 at least partially throughcomposite laminate 14 after infusion of flowable matrix material 16 intoporous region 12 and subsequent curing where structural pin 44 isdisposed inside column 50.

Formed hole 42 may have the same characteristics as described above. Invarious embodiments, structural pin 44 may be made of metal (e.g.,steel, copper, titanium), glass, graphite or carbon fibres. In someembodiments, structural pin 44 may comprise fibrous material (e.g.,carbon fibres). Structural pin 44 may be inserted into hole 42 beforeinfusion of flowable matrix material 16 into hole 42 and into space(s)in porous region 12. Structural pin 44 may have a pin diameter DP thatis smaller than the hole diameter DH in order to form passageway 54along hole 42 between structural pin 44 and a wall of hole 42. Suchpassageway 54 may be configured to permit the flow of flowable matrixmaterial 16 into hole 42 so as to facilitate the infusion of flowablematrix material 16 into porous region 12 of composite laminate 14. Insome embodiments, a ratio of the diameter DP of structural pin 44 overthe diameter DH of hole 42 may be about ⅔. For example, in oneembodiment, hole 42 may have a diameter of about 0.75 mm and structuralpin 44 may have a diameter DP of about 0.5 mm.

The characteristics of structural pin 44 may be selected based on thestructural and physical properties desired from the presence ofstructural pin 44 in the repaired composite laminate 14. For example,the material(s) of structural pin 44 may be selected in view of desiredelectromagnetic interference (EMI), electromagnetic compatibility (EMC),high intensity radiated fields (HIRF) performance, coefficient ofthermal expansion and/or other factors. Structural pin 44 may alsoprovide reinforcement through the thickness (e.g., transverse, in the Zdirection) of composite laminate 14 after infusion by allowing theformation of column 50 of cured flowable matrix material 16 andstructural pin 44 disposed therein extending between plies 52 ofcomposite laminate 14 and may be referred as a “Z-pin”. Thecross-sectional area of passageway 54 may be selected based on theexpected viscosity of flowable matrix material 16 so that flowablematrix material 16 may flow adequately into hole 42 and aroundstructural pin 44. The sizes of hole 42 and structural pin 44 may beselected based on a desired corresponding size of column 50 of curedflowable matrix material 16 with structural pin 44 disposed therein. Insome embodiments, structural pin 44 may be longer than the depth LH ofhole 42 so that structural pin 44 protrudes from face 18 by theprotruding height PH. The protruding height PH may provide an indicationof the depth LH of hole 42 for the purpose of (e.g., visual)verification prior to infusion. The protruding height PH of structuralpin 44 may be maintained for the infusion process. The use of flexible(e.g., rubber) caul plate 46 may substantially prevent vacuum barrier 20from getting damaged or punctured due to the evacuation of volume 24during infusion.

As shown in FIG. 6B, the protruding height PH of structural pin 44 maybe removed by grinding or cutting for example after curing of flowablematrix material 16 so that, for example, the upper end of structural pin44 may be substantially flush with face 18. In some embodiments, thepresence of structural pin 44 inside of column 50 of cured flowablematrix material 16 may provide additional structural reinforcement incomparison with a column 50 of cured flowable matrix material 16 withoutstructural pin 44 therein. Structural pin 44 may extend generally alongcolumn 50 of cured flowable matrix material 16.

FIG. 7 is a perspective view of an exemplary first portion 28 of face 18of composite laminate 14 where porous region 12 comprises dry fibers.FIG. 7 shows an outer ply 52 of composite laminate 14 having a 5-harnessconfiguration and through which a plurality of holes 42 has been formedand a structural pin 44 has been inserted into each hole 42. Theplurality of holes 42 (and structural pins 44) may be arranged in anarray with spacing selected based on a determined need forassisting/facilitating the infusion of flowable matrix material 16 intoporous region 12 via holes 42 and may be based on the size and depth ofporous region 12. Alternatively, the spacing and arrangement of holes 42and structural pins 44 may be based on the structural reinforcementdesired in repaired composite laminate 14 via column 50 and structuralpin 44.

FIG. 8 is an enlarged perspective view of an exemplary hole 42 formed inface 18 of composite laminate 14 with structural pin 44 extendingtherein.

FIG. 9 is a flowchart illustrating an exemplary method 900 for repairingcomposite laminate 14 by infusion of flowable matrix material 16 into aspace (e.g., defect, crack, delamination, porous region 12) in thecomposite laminate 14. In some embodiments, method 900 may be performedusing apparatus 10 described above where face 18 of composite laminate14 comprises area 22 overlaying a location of porous region 12 incomposite laminate 14. Method 900 or part(s) thereof may be performed inconjunction with method 400 or other methods disclosed herein. Method900 may comprise infusing flowable matrix material 16 into the space viapassageway 54 defined between optional structural pin 44 disposed inhole 42 extending from face 18 (or from other surface of compositelaminate 14) at least partially through composite laminate 14 (e.g., andinto the space in composite laminate 14), and, a wall of hole 42 (seeblock 902).

In methods 400 and/or 900, the detection of flowable matrix material 16overflowing space (e.g., porous region 12) via second portion 36 of area22 may be used as an indication that the space into which flowablematrix material 16 is being infused is sufficiently filled. Accordingly,methods 400 and/or 900 may comprise detecting some flowable matrixmaterial 16 exiting porous region 12 via second portion 36 of area 22and ceasing the drawing/infusion of flowable matrix material 16 afterhaving detected some of flowable matrix material 16 having exited porousregion 12 via second portion 36. Such detection may be made by visualinspection of some operator of apparatus 10 or by some automatedsensing/detecting equipment. In some embodiments, the detection ofoverflow of flowable matrix material 16 may be made by detecting thepresence of flowable matrix material 16 exiting vacuum port 38 or bydetecting the presence of flowable matrix material 16 in a suitableresin trap installed between vacuum port 38 and the vacuum source 40.

Methods 400 and/or 900 may comprise curing flowable matrix material 16infused into the space (e.g., porous region 12 or other defect) and intopassageway 54 while structural pin 44 is in formed hole 42 (see block904).

In some embodiments, methods for infusing flowable matrix material 16into a space inside composite laminate 14 may comprise infusing flowablematrix material 16 into the space via passageway 54 as explained abovein relation to porous region 12. Alternatively, in some embodiments,methods disclosed herein may comprise infusing flowable matrix material16 into passageway 54 via the space (e.g., defect) in composite laminate14 (i.e., in the opposite direction) as explained below in relation toedge delamination. Accordingly, in some embodiments, method 900 maycomprise detecting some of flowable matrix material 16 having enteredpassageway 54 and ceasing to infuse flowable matrix material 16 into thespace after having detected some of flowable matrix material 16 havingentered passageway 54.

FIG. 10 is a perspective view of an edge 56 of composite laminate 34where edge 56 comprises delamination damage 58. Such edge delaminationdamage 58 may be caused, for example, by one or more impacts to edge 56of composite laminate 34 during handling or during use of compositelaminate 34. Delamination damage 58 may comprise empty space (e.g.,void(s), crack(s)) formed inside composite laminate 34 due to edgedelamination. The empty space may be disposed between adjacent plies 52and may be in the form of a crack extending from edge 56 and to somedepth inside composite laminate 34. Traditional methods for repairingsuch edge delamination damage 58 may not have the ability to get resinto sufficient depth or to the crack tip inside composite laminate 34. Asa result voids may remain inside parts repaired by traditional repairmethods and affect structural performance. In various embodiments,apparatus and methods disclosed herein may be used to repair suchdelamination defect by resin infusion in order to achieve more completefiling of the space formed inside composite laminate 14 due to edgedelamination. In some embodiments, apparatus and methods disclosedherein may be used to also provide through-thickness structuralreinforcement via column 50 and optionally structural pin 44 to increasethe resistance to further (e.g., impact) damage.

As shown in FIG. 10 delamination damage 58 may include multilayerdelamination which may, for example, occur in composite laminate 14.Alternatively, delamination damage 58 may include single-layerdelamination. For the purpose of the present disclosure, an “edge” ofcomposite laminate 14 is intended to represent a surface of compositelaminate 14 extending generally transversely to individual plies 52 (seeFIG. 5A) of composite laminate 14 and at which individual plies 52terminate as shown by reference character 56 in FIG. 10. Edge 56 ofcomposite laminate 14 may not necessarily be perpendicular to face 18and may be at an oblique angle to face 18.

FIG. 11 is a schematic cross-sectional illustration of an exemplaryapparatus 60 for repairing delamination damage 58 in composite laminate14 by infusion of flowable matrix material (e.g., resin) 16 via edge 56of composite laminate 14. Apparatus 60 may be used to at least partiallyfill space(s) (e.g., void(s), crack(s)) inside composite laminate 14 dueto delamination damage 58 in a stepwise manner in order to obtain morecomplete filling of such space(s) relative to traditional repairmethods.

Apparatus 60 may comprise vacuum barriers 20A-20C and sealing members 26together defining a plurality of inboard zones A-C at differentdistances from edge 56 of composite laminate 34. For example, in thecase where apparatus 60 defines three inboard zones, zone A may bedisposed at a first distance from edge 56, zone B may be disposed at asecond distance from edge 56 where the second distance is greater thanthe first distance, and, zone C may be disposed at a third distance fromedge 56 where the third distance is greater than the second distance.The number and size of zones A-C may be selected based on the extent(e.g, depth, spread) of delamination damage 58 to be repaired.Similarly, the number of inlet ports 29 may be selected based on theextent (e.g, depth, spread) of delamination damage 58 to be repaired.The extent of delamination damage 58 may be determined by way ofnon-destructive (i.e., ultrasound) inspection and such information maybe used to determine the number and positions of zones A-C accordingly.The use of zones A-C may permit the progressive infusion of flowablematrix material 16 into delamination damage 58 in a stepwise manner asdescribed below.

Each inboard zone A-C may comprise the same elements configured in asimilar manner so the following description is directed to zone A only.It is understood that some elements from apparatus 10 described aboveare also found in apparatus 60 and therefore their description is notrepeated. Like elements are referenced using like reference numerals.With respect to zone A, vacuum barrier 20A, seals 26 and face 18 ofcomposite laminate 14 may define enclosed volume 24A in fluidcommunication with the space in composite laminate 14 associated withdelamination damage 58 via formed hole 42A in face 18 of compositelaminate 14. A supply of flowable matrix material 16 may be coupled tothe space in composite laminate 14 associated with delamination damage58 via edge 56 of composite laminate 34. For example, the supply offlowable matrix material 16 may be in fluid communication withdelamination damage 58 via inlet port 29. Apparatus 60 may comprisevacuum source 40 coupled to volume 24A for causing flowable matrixmaterial 16 to flow from edge 56 of composite laminate 14 into formedhole 42A via the space associated with delamination damage 58.

Vacuum source 40 may be coupled to volume 24A via vacuum port 38A.Apparatus 60 may comprise a suitable 62A valve of known or other typeactuatable from an open position to a closed position where the openposition permits a vacuum to be drawn (fluid flow) through vacuum port38A and the closed position substantially prevents fluid flow throughvacuum port 38A. Even though the exemplary embodiment shown in FIG. 11comprises a single vacuum source 40 coupled to a plurality of volumes24A-24C, it is understood that different vacuum sources 40 could becoupled to different volumes 24A-24C. For example, in some embodiments,each volume 24A-24C could have its own dedicated vacuum source 40.

Apparatus 60 may comprise other elements omitted from FIG. 11 for thesake of clarity. For example, apparatus 60 may also comprise flexiblecaul plate 46, one or more release films 48, and one or more porousrelease media 49 described above in relation to apparatus 10. Forexample, a suitable release film 48 may be disposed between vacuumbarrier 20 and overflow carrier 34 of each zone. Similarly, a suitableporous release medium 49 may be disposed between overflow carrier 34 andface 18 of composite laminate 14.

In various embodiments, volume 24A may be closer to edge 56 of compositelaminate 34 than volume 24B. Similarly, volume 24B may be closer to edge56 of composite laminate 34 than volume 24C. Accordingly, each zones A-Cmay be used sequentially, non-sequentially or concurrently duringinfusion to progressively infuse flowable matrix material 16 deeper intocomposite laminate 14 and to provide more complete filing ofdelamination damage 58.

FIG. 12A is a partial schematic cross-sectional view of compositelaminate 14 at formed hole 42 extending from face 18 at least partiallythrough composite laminate 14 before infusion of flowable matrixmaterial 16 into delamination damage 58. FIG. 12B is a partial schematiccross-sectional view of composite laminate 14 at a corresponding column50 of cured flowable matrix material 16 extending from face 18 at leastpartially through composite laminate 14 and volume 53 of cured flowablematrix material 16 having been infused into delamination damage 58 andcured.

Formed hole 42 may be used in conjunction with the apparatus and methodsdisclosed herein to facilitate the infusion of flowable matrix material16 into delamination damage 58 or other defect within composite laminate14. The characteristics of formed hole 42 may be the same as to thosepreviously described above unless otherwise indicated. The depth LH ofhole 42 may be selected based on the depth of delamination damage 58.Depth LH may be selected to extend through two or more plies 52 ofcomposite laminate 14. Formed hole 42 may be used to provide structuralreinforcement across the thickness (e.g., transverse, in the Zdirection) of composite laminate 14 after repair by allowing theformation of column 50 of cured flowable matrix material 16 extending atleast partially through composite laminate 14.

FIG. 13A is a partial schematic cross-sectional view of compositelaminate 14 at formed hole 42 extending from face 18 at least partiallythrough composite laminate 14 where structural pin 44 has been insertedinto formed hole 42 before infusion of flowable matrix material 16 intodelamination damage 58. FIG. 13B is a partial schematic cross-sectionalview of composite laminate 14 at a corresponding column 50 of curedflowable matrix material 16 extending from face 18 at least partiallythrough composite laminate 14 after infusion of flowable matrix material16 into delamination damage 58 and subsequent curing where structuralpin 44 is disposed inside column 50.

Formed hole 42 and structural pin 44 may have the same characteristicsas described above unless otherwise indicated. Structural pin 44 may beinserted into formed hole 42 before infusion of flowable matrix material16 into formed hole 42 and into delamination damage 58. Structural pin44 may have a pin diameter DP that is smaller than the hole diameter DHin order to form passageway 54 along hole 42 between structural pin 44and a wall of hole 42. Such passageway 54 may be configured to permitthe flow of flowable matrix material 16 into hole 42 so as to facilitatethe infusion of flowable matrix material 16 into delamination damage ofcomposite laminate 14.

Structural pin 44 may provide reinforcement across the thickness (e.g.,transverse, in the Z direction) of composite laminate 14 after repair byallowing the formation of column 50 of cured flowable matrix material 16and structural pin 44 disposed therein extending between plies 52 ofcomposite laminate 14.

As shown in FIG. 13B, the protruding height PH of structural pin 44 maybe removed by grinding or cutting for example after curing of flowablematrix material 16 so that the upper end of structural pin 44 may, forexample, be substantially flush with face 18.

FIG. 14 is a perspective view of part of an apparatus 60 comprising onlytwo zones A and B.

FIG. 15 is a flowchart illustrating an exemplary method 1500 forrepairing edge delamination damage 58 in composite laminate 14 byinfusion of flowable matrix material 16 via edge 56 of compositelaminate 14. Method 1500 may be performed using apparatus 60. Aspects ofmethod 1500 may be applicable to other methods disclosed herein. Invarious embodiments, method 1500 may comprise: supplying flowable matrixmaterial 16 at a location of edge 56 of composite laminate 16 (see block1502) where the edge location is in fluid communication with a space incomposite laminate 14 associated with the delamination; infusingflowable matrix material 16 into the space associated with thedelamination in composite laminate 14 using a pressure differentialbetween the edge location and a first inboard location (e.g., formedhole 42A in FIG. 11) in composite laminate 14 where the first inboardlocation is in fluid communication with the edge location via the spacein composite laminate 14 associated with the delamination (see block1504); and curing flowable matrix material 16 infused into the space incomposite laminate 14 associated with the edge delamination.

A pressure at the first inboard location may be lowered relative to apressure at the edge location to draw flowable matrix material 56 fromthe edge location toward the first inboard location. In someembodiments, the pressure at the first inboard location may be loweredvia formed hole 42A extending at least partially through compositelaminate 14 from face 18 of composite laminate 14.

Flowable matrix material 16 may be infused into formed hole 42A.Structural pin 44 may extend into hole 42A and flowable matrix material16 may be infused into passageway 54 defined between a wall of formedhole 42A and structural pin 44. Flowable matrix material 16 infused intohole 42A may be cured while structural pin 44 is in hole 42A.

Some of flowable matrix material 16 having been infused into hole 42Amay be detected and infusion of flowable matrix material 16 into thespace associated with the delamination in composite laminate 14 may beceased after having detected some of flowable matrix 16 material havingbeen infused into hole 42A.

In some embodiments, method 1500 may be modified so that flowable matrixmaterial 16 is caused to flow in the opposite direction where flowablematrix material 16 may be infused into edge delamination damage 58 viaformed hole(s) 42 and caused to flow toward (and optionally out) of edgedelamination damage 58 via edge 56 of composite laminate 14. In suchembodiment, one or more zones A, B, C shown in FIG. 11 and coupled tovacuum source(s) 40 may be disposed at edge 56 and the supply offlowable matrix material 16 may be in communication with one or moreformed holes 42 via face 18 of composite laminate 14.

FIG. 16 is a flowchart illustrating an exemplary method 1600 forrepairing edge delamination damage 58 in composite laminate 14 byinfusion of flowable matrix material 16. Method 1600 may be performedusing apparatus 60 or a variation of apparatus 60 modified to causeflowable matrix material to flow in the opposite direction. Aspects ofmethod 1500 disclosed above may also be applicable to method 1600 ininstances where flowable matrix material 16 is supplied via edge 56 ofcomposite laminate 14. In various embodiments, method 1600 may comprise:infusing flowable matrix material 16 into the space associated with theedge delamination (e.g., edge delamination damage 58) in compositelaminate 14 using a pressure differential between a first inboardlocation (e.g., formed hole 42A in FIG. 11) on composite laminate 14 andan edge location (e.g., edge 56) on composite laminate 14 where thefirst inboard location is in fluid communication with the edge locationvia the space in composite laminate 14 (see block 1602); and curingflowable matrix material 16 infused into the space in composite laminate14 associated with the edge delamination (see block 1604).

Method 1600 may comprise infusing the flowable matrix material 16 intothe space via edge 56 as explained above in relation to apparatus 60 andmethod 1500. Alternatively, method 1600 may comprise infusing flowablematrix material 16 into the space via the first inboard location.Accordingly, method 1600 may comprise lowering a pressure at edge 56relative to a pressure at the first inboard location (e.g., formed hole42A in FIG. 11) to draw flowable matrix material 16 from the firstinboard location toward edge 56. Flowable matrix material 16 may beinfused via formed hole(s) 42A extending at least partially throughcomposite laminate 14 from face 18 of composite laminate 14.

Flowable matrix material 16 may be infused into the space associatedwith the delamination in laminate composite 14 using a pressuredifferential between the edge location and a second inboard location(e.g., formed hole 42B) in composite laminate 14 where the secondinboard location is in fluid communication with the edge location viathe space in laminate composite 14 associated with the delamination. Invarious embodiments, a pressure at the second inboard location may belowered so as to draw flowable matrix material 16 from edge 56, or,alternatively, flowable matrix material 16 may be infused into the spacevia the second inboard location while a pressure at edge 56 is loweredso as to draw flowable matrix material 16 from the second inboardlocation toward edge 56.

Methods disclosed herein may comprise ceasing to infuse flowable matrixmaterial 16 into the space associated with the delamination in compositelaminate 14 using the first inboard location before infusing flowablematrix material 16 into the space associated with the delamination incomposite laminate 14 using the second inboard location. In someembodiments, the first inboard location may be substantiallyhermetically sealed off (e.g., via valve 62A) before infusing flowablematrix material 16 into the space associated with the delamination incomposite laminate 14 using the second inboard location. As shown inFIG. 11, the first inboard location (e.g., formed hole 42A) may be at afirst distance from edge 56 and the second inboard location (e.g.,formed hole 42B) may be at a second distance from edge 56. The seconddistance may be greater than the first distance.

FIG. 17 is a flowchart illustrating an exemplary method 1700 forinfusing flowable matrix material 16 into a space in composite laminate14. Method 1700 may be performed using apparatus 60 to provide aprogressive infusion into delamination damage 58 in a stepwise manner.Aspects of method 1700 may be applicable to other methods disclosedherein. In various embodiments, method 1700 may comprise: supplyingflowable matrix material 16 at an inlet location (e.g., inlet port 29,edge 56) in composite laminate 14 where the inlet location is in fluidcommunication with the space in composite laminate 14 (see block 1702);infusing flowable matrix material 16 into the space in compositelaminate 14 using a pressure differential between the inlet location anda first location (e.g., formed hole 42A) in composite laminate 14 wherethe first location is in fluid communication with the inlet location viathe space in the composite laminate 14 (see block 1704); ceasing toinfuse flowable matrix material 16 into the space using the firstlocation (see block 1706); infusing flowable matrix material 16 into thespace in composite laminate 14 using a pressure differential between theinlet location and a second location (e.g., driled hole 42B) oncomposite laminate 14 where the second location is in fluidcommunication with the inlet location via the space in compositelaminate 14 (see block 1708); and ceasing to infuse flowable matrixmaterial 16 into the space using the second location (see block 1710).

In some embodiments, the first location may be at a first distance fromthe inlet location and the second location may be at a second distancefrom the inlet location. The second distance may be greater than thefirst distance.

A pressure at the first location may be lowered relative to a pressureat the inlet location via first formed hole 42A extending at leastpartially through composite laminate 14 from face 18 of compositelaminate 14. Infusion of flowable matrix material 16 into the space incomposite laminate 14 using first formed hole 42A may be ceased aftersome of flowable matrix material 16 has entered first formed hole 42A.In some embodiments, first formed hole 42A may be hermetically sealedoff (e.g., via valve 62A) before infusing flowable matrix material 16into the space in composite laminate 14 using the second location (e.g.,second formed hole 42B). Flowable matrix material 16 that has enteredfirst formed hole 42A may be cured while first structural pin 44A is infirst formed hole 42A.

A pressure at the second location may be lowered relative to thepressure at the inlet location via second formed hole 42B extending atleast partially through composite laminate 14 from face 18 of compositelaminate 14. Infusion of flowable matrix material 16 into the space incomposite laminate 14 using second formed hole 42B may be ceased aftersome of flowable matrix material 16 has entered second formed hole 42B.Flowable matrix material 16 that has entered second formed hole 42B maybe cured while first structural pin 44B is in first formed hole 42B.

The above description is meant to be exemplary only, and one skilled inthe relevant arts will recognize that changes may be made to theembodiments described without departing from the scope of the inventiondisclosed. For example, the blocks and/or operations in the flowchartsand drawings described herein are for purposes of example only. Theremay be variations made to these blocks and/or operations withoutdeparting from the teachings of the present disclosure. The presentdisclosure may be embodied in other specific forms without departingfrom the subject matter of the claims. Also, one skilled in the relevantarts will appreciate that while the apparatus and methods disclosed andshown herein may comprise a specific number of elements/steps, theapparatus and methods could be modified to include additional or fewerof such elements/steps. The present disclosure is also intended to coverand embrace all suitable changes in technology. Modifications which fallwithin the scope of the present invention will be apparent to thoseskilled in the art, in light of a review of this disclosure, and suchmodifications are intended to fall within the appended claims. Also, thescope of the claims should not be limited by the preferred embodimentsset forth in the examples, but should be given the broadestinterpretation consistent with the description as a whole.

1. An apparatus for infusing a flowable matrix material into a porousregion in a composite laminate via a surface of the composite laminate,the apparatus comprising: a vacuum barrier covering at least a firstportion of an area of the surface of the composite laminate overlaying alocation of the porous region in the composite laminate, the vacuumbarrier defining an enclosed volume comprising the first portion of thearea of the surface of the composite laminate; a supply of flowablematrix material available to the first portion of the area of thesurface of the composite laminate; a flow barrier hindering a flow ofthe flowable matrix material out of the first portion of the area viathe surface of the composite laminate, the flow barrier being positionedbetween the first portion of the area and a second portion of the area,the second portion of the area being outside the first portion of thearea; and a vacuum source in fluid communication with the enclosedvolume and configured to cause the flowable matrix material in the firstportion of the area to be drawn into the porous region, the vacuumsource being in fluid communication with the second portion of the areato draw the flowable matrix material out of the porous region via thesecond portion of the area.
 2. The apparatus as defined in claim 1,wherein the vacuum barrier also covers the second portion of the areaand the enclosed volume includes the second portion of the area.
 3. Theapparatus as defined in claim 1, further comprising: a first carrierconfigured to facilitate the distribution of flowable matrix materialacross at least some of the first portion of the area; and a secondcarrier configured to facilitate the flow of flowable matrix materialexiting the second portion of the area toward the vacuum source.
 4. Theapparatus as defined in claim 3, wherein the flow barrier comprises agap between the first carrier and the second carrier.
 5. The apparatusas defined in claim 4, wherein the flow barrier comprises a release filmoverlaying the first and second carriers and extending across the gapbetween the first carrier and the second carrier.
 6. The apparatus asdefined in claim 1, wherein the composite laminate comprises a formedhole extending at least partially through the composite laminate fromthe surface inside the first portion of the area to facilitate theinfusion of flowable matrix material into the porous region, and, theapparatus comprises a structural pin extending into the formed hole, thestructural pin being configured to define a passageway for the flowablematrix material between the structural pin and a wall of the formedhole.
 7. The apparatus as defined in claim 6, wherein the structural pinprotrudes from the surface of the composite laminate.
 8. The apparatusas defined in claim 6, wherein the structural pin comprises fibrousmaterial.
 9. The apparatus as defined in claim 1, further comprising aflexible caul plate disposed inside the enclosed volume.
 10. A methodfor infusing a flowable matrix material into a porous region in acomposite laminate via a surface of the composite laminate, the surfacecomprising an area overlaying a location of the porous region in thecomposite laminate, the method comprising: supplying the flowable matrixmaterial to a first portion of the area of the surface of the compositelaminate; distributing the flowable matrix material across at least someof the first portion of the area of the surface; and while hindering aflow of the flowable matrix material out of the first portion of thearea via the surface of the composite laminate, drawing the flowablematrix material in the first portion of the area into the porous regionand causing some of the flowable matrix material to exit the porousregion via a second portion of the area outside the first portion of thearea.
 11. The method as defined in claim 10, further comprising: using avacuum source to draw the flowable matrix material into the porousregion; and facilitating the flow of flowable matrix material exitingthe porous region via the second portion away from the second portion.12. The method as defined in claim 10, further comprising forming a holethrough the surface of the composite laminate in the first portion ofthe area defining the location of the porous region, the hole beingformed before drawing the flowable matrix material to facilitate thedrawing of flowable matrix material into the porous region.
 13. Themethod as defined in claim 12, further comprising providing a structuralpin in the formed hole where a passageway for the flowable matrixmaterial is defined between the structural pin and a wall of the formedhole, the structural pin being provided before drawing the flowablematrix material.
 14. The method as defined in claim 13, furthercomprising curing the flowable matrix material drawn into the porousregion and that has entered the formed hole, while the structural pin isin the formed hole.
 15. The method as defined in claim 10, furthercomprising detecting some of the flowable matrix material exiting theporous region via the second portion of the area and ceasing the drawingafter having detected some of the flowable matrix material having exitedthe porous region via the second portion. 16.-54. (canceled)
 55. Amethod for infusing a flowable matrix material into a space in thecomposite laminate, the method comprising: supplying the flowable matrixmaterial at an inlet location on the composite laminate, the inletlocation being in fluid communication with the space in the compositelaminate; infusing the flowable matrix material into the space in thecomposite laminate using a pressure differential between the inletlocation and a first location in the composite laminate, the firstlocation being in fluid communication with the inlet location via thespace in the composite laminate; ceasing to infuse the flowable matrixmaterial into the space using the first location; infusing the flowablematrix material into the space in the composite laminate using apressure differential between the inlet location and a second locationin the composite laminate, the second location being in fluidcommunication with the inlet location via the space in the compositelaminate; and ceasing to infuse the flowable matrix material into thespace using the second location.
 56. The method as defined in claim 55,wherein the first location is at a first distance from the inletlocation and the second location is at a second distance from the inletlocation, the second distance being greater than the first distance. 57.The method as defined in claim 55, further comprising lowering apressure at the first location relative to a pressure at the inletlocation via a first formed hole extending at least partially throughthe composite laminate from a face of the composite laminate.
 58. Themethod as defined in claim 57, further comprising ceasing to infuse theflowable matrix material into the space associated with the delaminationin the composite laminate using the first formed hole after some of theflowable matrix material has entered the first formed hole.
 59. Themethod as defined in claim 57, further comprising hermetically sealingthe first formed hole before infusing the flowable matrix material intothe space in the composite laminate using the second location.
 60. Themethod as defined in claim 58, further comprising curing the flowablematrix material that has entered the first formed hole while a firststructural pin is in the first formed hole.
 61. The method as defined inclaim 57, further comprising lowering a pressure at the second locationrelative to the pressure at the inlet location via a second formed holeextending at least partially through the composite laminate from theface of the composite laminate.
 62. The method as defined in claim 61,further comprising ceasing to infuse the flowable matrix material intothe space associated with the delamination in the composite laminateusing the second formed hole after some of the flowable matrix materialhas entered the second formed hole.
 63. (canceled)